Nikki was feeling perfectly fine despite the changes, yet she went to the hospital just in case. Regardless of what she said, she couldn't convince Maya not to accompany her.
At the hospital they were quickly attended to, the doctor who received them being the same one who had attended Maya when she was infected with the virus.
"Hi, can you get used to your new self?" the doctor said
"I'm great, couldn't be better." Maya said
"So how can I help you if you don't have any problems?" the doctor asked
"It's my friend here who is your patient." Maya said pointing to Nikki
"Hi. I only came because I also got infected with the virus and I changed yesterday, but when I woke up today I was pretty much back to normal." Nikki said
"This is very strange. It shouldn't happen, at least there's no recorded case of anyone returning to normal after the mutation. Please tell me the details." Please tell me the details. "Understand. I'm going to run some tests so I'd like you guys to wait a bit in the waiting room." the doctor said and took some of Nikki's blood before heading to the exam room.
****
After about two hours waiting, the doctor called them again.
"I managed to find something. As far as we know the animal from which a person infected by the virus acquires characteristics is not random, the person always acquires characteristics of the animal that infected them." the doctor said
"That's why I'm part dog now, because I was infected by my dog." Maya said
"Exactly. Another characteristic is that if a person infects another, it makes him acquire the same characteristics of the same animal as him. It turns out that in your case you have a different blood type and that affects the virus." the doctor said
"What do you mean a different blood type?" Nikki asked
"It's just that aside from the blood types that everyone knows there are some different ones that are extremely rare, so rare that at most a few dozen people around the world have them, and you happen to be one of them. His blood is known as Bombay or 'False O'. Your single blood is affecting the virus in order to erase the animal information from your genetic code, it's a very slow process, but it accelerates while you sleep, it makes you go back to normal." the doctor said
"If so then why didn't I notice anything yesterday?" Nikki asked
"is it not because we were together all day, including having sex several times." Maya said
"It makes sense what you say. Probably each new contact reactivates the animal charge in you causing you to reacquire the animal's characteristics." the doctor said and put his finger on his chin, thought for a moment and then asked "Maybe that doesn't help at all, but you wouldn't mind passing an extra test. You can be soothed that it won't hurt you..
"If it helps to better understand what happened to me, I don't see any problem." Nikki said
"Excellent." the doctor said, them he picked up the phone and called someone, that when it was answered the girls heard him saying "Hello, could you ask Tiffany to come to my office? ..... I know she is on her break time. Just say she has sex involved and she won't complain..... Alright, I'll be waiting."
When they heard the doctor say that sex would have involved both Nikki and Maya they felt their dicks harden, increasing the size of the bulges in their pants, which the doctor noticed.
"I think it's great that you guys are excited about the audition but I'm sorry to inform you that you won't be able to join them Maya." the doctor said
"That's not fair. Why do I have to stay out?" Maya said
"It's because I want to know what will happen if she has a relationship with an infected person who become hybrid to a different animal. Normally someone who has already mutated can no longer be affected by the virus, but in addition to Nikki returning to being fully human, she has maintained her canine characteristics while in constant contact with you. If you join them you can compromise the test." the doctor said
"I get it. But can I at least watch?" Maya asked
"You can, as long as you keep a safe distance." the doctor said
Nikki just listened and it was a shame for her that Maya couldn't participate, she was so anxious and excited that her hard cock almost ached for it, but she decided to wait.
We didn't even have to wait 5 minutes, the office door and Tiffany came in saying "What's up doctor? Did you send for me?" Nikki and Maya looked at her and saw a nurse. At first glance she looked like a normal woman with her tanned skin, her eyes and long black hair, and ample breasts, but instead legs she had a long snake tail.
"I called yes. I need you to have sex with this girl here for a test." the doctor said pointing to Nikki.
"But doctor? You know I have the virus and it is contagious, if I have sex with her I will infect her." Tiffany said. The doctor then informed her of the situation, which made her understand what was happening. "Great, so my role in all of this is just to have sex with her and report what happens. This is going to be very easy." she said and turned to leave the room indicating for Nikki and Maya to follow her.
The girls were taken to a wing of the hospital that was under construction, which they were told was part of the expansion of the building and was not yet in use and so they wouldn't bother anyone there. They entered a finished room, which was completely empty, and closed the door behind them.
"Okay, here we won't have to hold back. You can now take off your clothes." Tiffany said quickly taking off her uniform. The nurse, like her patient, also had a dick and pussy practically hidden behind her balls positioned exactly where her human skin met the scales of her tail.
Maya took her clothes off and sat in a corner of the room saying "Too bad I can't participate so I'll just masturbate while watching from here."
"Don't worry Maya, we'll make up for it later." Nikki said while taking off her clothes
Tiffany then grabbed Nikki and lifted her, positioned her over her own hard member and lowered her, penetrating the human girl's pussy.
Nikki was finding the experience interesting, having a snake stick inside her after having had a dog stick the day before. She then started jacking off while getting fucked. It didn't take her long to feel that something was different, her dick was weird and her legs were too soft. Looking down the patient saw that her dick was changing shape and her legs had acquired scales.
"It seems.... that.... I.... am.... becoming.... a lamia.... too." Nikki said slowly in the excitement of being fucked by the nurse.
"Really interesting." was all Tiffany said before continuing to fuck Nikki, whose legs quickly merged and began to elongate into an undeniable snake tail. When the two finally came, Nikki had completed her transformation and was now a lamia too.
"I changed again, but into a different species now. I really got big now." Nikki said, looking at her snake tail and trying to guess how long she was now.
"Do you want to know the size of your body? You look like you're about the same size as me, so your tail should be about 20 feet long." Tiffany said
"And even? I think I would have trouble moving in my own room like this." Nikki said